Meta descriptions for web pages likely won’t influence the rankings of your web pages in search results. But if your meta descriptions include keywords that your pages might be found for, they may be displayed in search results with links to those pages. If those meta descriptions are interesting and engaging and provide the right information, they may influence people who view them and are interested in what you offer to visit your pages.

When someone searches at a search engine, they are usually presented with a list of search results, often referred to as SERPS – search engine result pages, including page titles, abstracts, or snippets from those pages and URLs from the pages. The abstracts or snippets may sometimes be part or all meta descriptions for the pages if the meta descriptions contain the keyword or keywords used by searchers in their queries.

But, a search engine might just as easily take that snippet from somewhere else on the page returned in search results. How does a search engine evaluate the search results that it might show?

If you spend a fair amount of time trying to find the right words to use in those meta descriptions, you may want to think about what might snippets appear when your pages show up in search results and the search engines don’t use those painfully and carefully crafted meta descriptions.

If I look up “nine inch nails,” I’m shown the following result:

search results for a Google search for [nine inch nails].

If I expand my query to include Trent Reznor’s last name -“nine inch nails reznor” – I’m shown a completely different snippet for the same page:

search results for a Google search for [nine inch nails reznor].

As you’re writing or editing the text for pages of your website, you may want to think about or see what queries people might be using or may try to use to find your web pages. Better snippets shown in search results may mean more visitors to your pages. It may be worth editing some of your copy to see if you can increase the number of visitors to those pages.

Search Engines and Evaluating Search Results

Search engines also are interested in showing snippets that meaningfully describe the pages they list in their search results. They might not show a meta description as a snippet because it doesn’t contain one of the keywords used in a searcher’s query, like in my [nine-inch nails reznor] query above.

Search engines would like to be perceived as returning meaningful and relevant results to searchers. If the snippets that they show don’t reflect that the pages they are returning in SERPS are relevant for the queries used to find them, people may use another search engine or perform a different search. For that reason, search engines also try to evaluate the search results that they return to searchers.

A Yahoo patent application published this week tells us a little about some of the methods they use to evaluate the search results and snippets that they show to searchers. The patent application is at:

Search Summary Result Evaluation Model Methods and Systems Assigned to Yahoo Invented by Tapas Kanungo and David M. Orr US Patent Application 20090187516 Published July 23, 2009 Filed January 18, 2008

Abstract

Methods and systems are provided herein for establishing and/or using an evaluation model that is adapted to determine a model judgment value based, at least in part, on measured summary feature values associated with a search result summary. The evaluation model may be established through a learning process based, at least in part, on human judgment values associated with a set of search result summaries.

The patent filing doesn’t go into a lengthy discussion about how the search engine might choose one string of text over another to display in place of a meta description. It doesn’t yield the answer to when a search engine will sometimes choose to use a title from DMOZ or the Yahoo Directory rather than the title of the page defined by the publisher of that page using a title element.

It does tell us that it will look carefully at the page title, the snippet, and the URL that it displays for a page to see if the words used in a query that found the page is included within those titles snippets and URLs.

The patent also tells us that it may use a search result summary evaluator to show the best search results. This evaluator uses a machine learning training system, which takes a set of human-reviewed search results for many entries, and tries to learn from those reviews so that the search engine can then create search results for other pages in an automated fashion.

In breaking down the different processes within the patent filing, the inventors discuss some aspects of that human training:

As part of the learning stage, at block 202, a data set of search result summaries may be established.

For example, one or more queries may be provided to a search engine to generate a set of search result summaries. Such queries may or may not be related.

At block 204, at least one user judgment value may be established for each search result summary. Here, for example, users may be presented with one or more search result summaries and asked to evaluate and score each search result summary about some criteria (e.g., relevance to a search query or topic, informative nature, etc.).

Such user judgment values may be more subjective and/or objective. Such user judgment values may represent an average of user judgment values from a plurality of users.

This training system may use a database to learn from where it collects sets of information about “queries, summaries, and user judgments” to evaluate the search results it creates.

Some information about the kind of features that the search engine might consider important in creating search result displays for pages. These may include such things as the “presence, style, location, and/or order of terms or portions thereof as presented within a search query.”

The adjacency or proximity of query terms may also play a role in the evaluation by the search engine of the quality of their search results:

Further, the location or proximity of two or more query terms or portions thereof concerning one another (e.g., closeness or separation) in the title may be measured, as may the ordering of such terms in the title.

For example, a search result summary may be perceived by a user to be more relevant if the terms in the title are more proximate in their respective location and/or more correctly ordered for their order in the original query.

If there is a “perfect” or substantial match of the original query terms (e.g., to the left, in the correct order, etc.) in the title, measuring such may help determine how relevant a user may perceive the search result summary.

Conclusion

This patent filing covers how a search engine might evaluate its own search results as they appear to searchers in SERPs, rather than telling us what it is looking for when it ranks pages to display in those search results.

It may hint at some things that may go into how a search engine might determine the relevancy of pages, but that isn’t the focus of the patent filing.

If you’re concerned about what shows up as a snippet for your pages in search results when a search engine decides to use something other than your meta description, you may want to spend some time reading through the patent application, as well as thinking about which terms and phrases your pages show up for in search results, and seeing what actually shows up as search results for those pages.